On the current Internet (Internet), the Internet Protocol (Internet Protocol, IP) address has double semantics, a locator (Locator) and an identifier (Identifier). The locator is used to indicate the topological location of a host on a network, and the identifier is used to indicate the identity of the host. With the increase of Internet users, rapid development of wireless networks, and increasing communication requirements of people, the practice of coupling the locator and identifier in the IP address leads to some problems, for example, the practice is disadvantageous to network layering and hinders the mutual access of hosts in different network coverage areas. Another serious problem is that using the IP address as the identifier does not support mobility well. However, with the tremendous development of current mobile communication, combining the mobile communication and the Internet will become an inevitable development trend of communication in the future. The Host Identity Protocol (Host Identity Protocol, HIP) is a solution for splitting the double semantics of the IP address. HIP introduces a host identity layer between a Transport Control Protocol (Transport Control Protocol, TCP) layer and an IP layer, and uses the host identity (Host Identity, HI) to identify a user. However, the IP address of the IP layer is only used for routing at a network layer, that is, the IP address reserves only the locator semantic, and the identifier semantic is represented by the HI of the HIP layer.
The HIP is used to identify the host; however, the final user of network communication is the user; in the case of inter-user communication, a user may pay less attention to the specific location of a peer user and devices used by the peer user, but pay more attention to who the peer user is. Therefore, using the host as the identifier cannot support a user-centered communication mode in the future.